Level 1 — Absolute Beginner

Many people cannot see things far away. This is called short sightedness. Glasses help them see.

Some people have laser surgery on the eye. A laser cuts a very thin piece of the eye away.

Now scientists tried a new way. They used a small piece of metal shaped like a contact lens. They also used a very small amount of electricity.

The front of the eye became soft for a short time. Then it took a new shape. It took about one minute. The test used rabbit eyes, not people.

eye

The part of the body that you see with.

glasses

Two pieces of glass in a frame that help you see.

laser

A very strong, narrow beam of light.

surgery

Medical work in which a doctor cuts the body.

metal

A hard material such as iron, gold or platinum.

electricity

The power that makes lights and machines work.

soft

Easy to bend or change shape.

shape

The form of something, such as round or flat.

Level 2 — Elementary

Laser eye surgery has helped millions of people stop wearing glasses, but it works by cutting and removing a thin layer of the cornea, the clear front window of the eye. That tissue never grows back, and the machines are expensive.

A team led by Michael Hill, a chemistry professor at Occidental College, and Brian Wong, a professor and surgeon at the University of California, Irvine, has tested a different idea. They press a platinum mould shaped like a contact lens onto the cornea and pass a very small electric current through it.

The current briefly changes the chemistry of the tissue and makes it soft enough to take the shape of the mould. When the current stops, the cornea firms up again in its new shape. The researchers call the method electromechanical reshaping.

In a test on twelve rabbit eyes, all ten that had been given simulated short sightedness were corrected in roughly one minute, and the cells in the treated eyes survived. The team warns that this is early work: the eyes were not in a living animal, and much more testing is needed before any human trial.

cornea

The clear front layer of the eye that light passes through.

tissue

A group of similar cells that make up part of the body.

mould

A hollow shape used to give something a new form.

current

A flow of electricity.

chemistry

The way substances behave and change.

simulated

Made artificially to be like the real thing.

survive

To stay alive.

trial

A careful test of a new treatment on people.

Level 3 — Intermediate

For nearly thirty years the standard answer to short sightedness has been a laser that vaporises a precisely calculated amount of corneal tissue. The procedure works well, but it is irreversible, it thins a structure that cannot regenerate, and the equipment keeps it out of reach in much of the world. A team of American researchers is now proposing something that sounds almost implausibly simple by comparison.

Michael Hill, a chemistry professor at Occidental College, and Brian Wong, a surgeon and professor at the University of California, Irvine, have developed what they call electromechanical reshaping. A platinum electrode shaped like a contact lens is placed against the cornea and a very small current is applied. The current alters the local acidity of the tissue, which loosens the molecular bonds holding the collagen network in place and lets the cornea relax into the curvature of the mould.

When the current is switched off, the chemistry reverts and the tissue stiffens again, now in its new shape. Nothing is cut and nothing is removed. In experiments on twelve rabbit eyes, ten of which had been made artificially short sighted, the intended optical correction was achieved in roughly a minute, and cell viability tests indicated that the treated tissue survived the procedure.

The caveats are substantial and the researchers state them plainly. The eyes were isolated specimens rather than those of living animals, which means the healing response, the immune reaction and the durability of the correction all remain unknown. Extensive animal work must come before any human trial. The funding came from the National Eye Institute and the John Stauffer Charitable Trust, and the team has also raised the possibility that the same approach might one day help with conditions such as keratoconus, in which the cornea bulges out of shape.

vaporise

To turn something into vapour, destroying it.

irreversible

Impossible to change back to how it was.

regenerate

To grow back after being damaged or removed.

electrode

A conductor through which electricity enters or leaves.

acidity

How acidic a substance is, measured on the pH scale.

collagen

A strong protein that gives structure to body tissue.

curvature

The amount by which a surface is curved.

viability

The ability of cells to stay alive and function.

Level 4 — Advanced

Refractive surgery has been remarkably successful and remarkably static. Since the mid nineteen nineties the dominant paradigm has been ablative: an excimer laser removes stromal tissue to a thousandth of a millimetre, the cornea assumes a flatter profile, and the patient walks out able to read a clock across the room. The trade offs are equally well established. The tissue is gone permanently, the residual bed imposes a hard limit on how much correction is possible, and the capital cost of the equipment confines the procedure largely to affluent markets.

Against that backdrop, the proposal from Michael Hill at Occidental College and Brian Wong at the University of California, Irvine, is conceptually disarming. Their technique, electromechanical reshaping, treats the cornea not as material to be subtracted but as a viscoelastic solid that can be temporarily plasticised. A platinum electrode contoured to the desired refractive geometry is applied to the surface, and a modest current drives a localised shift in pH. The acid environment disrupts the electrostatic and hydrogen bonding that stabilises the collagen matrix; the stroma yields; it conforms to the mould.

Cut the current and the chemistry relaxes, the bonds re form, and the tissue sets in its new configuration. In the reported series of twelve enucleated rabbit eyes, the ten rendered artificially myopic achieved their target correction in about sixty seconds, with cell viability assays indicating the keratocytes endured the exposure. No incision was made and no tissue was excised, which in principle removes the ceiling that residual stromal thickness imposes on conventional ablation.

None of which yet amounts to a clinical prospect, and the investigators are candid about it. Enucleated eyes have no wound healing cascade, no inflammatory response and no mechanism by which a correction might regress over months, and those are precisely the variables that have historically separated elegant benchtop results from durable ophthalmic practice. Supported by the National Eye Institute and the John Stauffer Charitable Trust, the group has flagged ectatic disease such as keratoconus as an adjacent target. The honest summary is that a genuinely novel physical mechanism has been demonstrated ex vivo, and that everything difficult remains ahead of it.

refractive

Relating to how the eye bends light to form an image.

ablative

Working by removing material from a surface.

stroma

The thick middle layer that forms most of the cornea.

viscoelastic

Behaving partly like a liquid and partly like a solid.

plasticise

To make a material soft enough to be reshaped.

enucleated

Removed from the body, said of an eye.

assay

A laboratory test that measures something precisely.